||| FROM USA TODAY |||
SAN FRANCISCO – A California ecosystem has gotten a big boost from an adorable, fluffy and hungry friend.
At Elkhorn Slough National Estuarine Research Reserve, a newly-reinvigorated population of native southern sea otters has eaten so many invasive European green crabs that researchers say the otters have locally solved a problem that has plagued the West Coast for years.
States are spending millions to protect their inland waterways from the tiny crabs. Though small – they reach only four inches in width – the invaders harm native wildlife and shoreline ecosystems. At stake are multi-million dollar shellfish industries for Dungeness, king crab and other species.
But at the reserve, otters have almost wiped the crabs out, helping the estuary’s ecosystem come back into balance.
“The otters are a just super voracious predator,” said Kerstin Wasson, research coordinator with the Reserve. “We calculated that the current otter population here eats somewhere between 50,000 and 120,000 green crabs a year.”
Green crabs are originally from Europe and arrived on the West coast sometime in the 1980s. They are considered one of the most invasive species in the marine environment, destroying seagrass, devouring baby crab and salmon and basically laying waste to coastal waters from California to Alaska.
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I’ve kayaked Elkhorn Slough and witnessed all the sea otters there, but did not realize they were going after the green crabs, too.
The Monterey Bay Aquarium uses the Slough to introduce rescued baby otters into the environment once they are deemed ready to join their fellow critters.
Maybe they could send us a few up here in the Salish Sea!
Washington and BC have their own sea otter populations so hopefully they’ll both continue to expand their ranges while snacking on green crabs (see https://wdfw.wa.gov/species-habitats/species/enhydra-lutris-kenyoni#desc-range and https://www2.gov.bc.ca/assets/gov/environment/plants-animals-and-ecosystems/species-ecosystems-at-risk/brochures/sea_otter.pdf).
The WA and BC populations are at the western ends of the Strait of Juan de Fuca and Queen Charlotte Sound. Near the ocean. They are very important in maintaining the viability of kelp forests, as they predate (eat) sea urchins.
Alaskans don’t like sea otters because they consume their local Dungeness crab populations.
Here we have river otters, who reproduce on land but hunt on the water. I don’t know if they eat green crabs, but they definitely consume Dungeness. They leave their shells on our boats and docks. They also reproduce in bacchanalian frenzies on our docks, late at night, during the summer. It’s something to hear.
Merry Christmas!